KR20160083004A - Electronic component and production method therefor - Google Patents

Abstract

A process for producing an electronic component using a casing material containing a silicone resin, the process comprising the steps of: adding aluminum hydroxide or magnesium hydroxide controlled in an amount of 60 wt% or more to less than 70 wt%; and a silicone resin to which a non- A step of drying the exterior material formed on the surface of the element to evaporate the non-polar solvent and exposing the silicone resin component to the surface of the exterior material; and a curing step of curing the exterior material. This makes it possible to reduce the silicon resin while maintaining the flame retardancy and the withstand voltage of the casing.

Description

ELECTRONIC COMPONENT AND PRODUCTION METHOD THEREFOR [0002]

TECHNICAL FIELD The present disclosure relates to electronic parts such as voltage nonlinear resistors and the like, and relates to a technique of smoothing or non-smoothing a covering material covering the device.

In a variety of appliances such as electronic devices and electric appliances, a combustible material such as plastic is used for the housing in order to lighten the weight. In addition, in the electronic parts, due to the request for miniaturization of the device, the packing density is increased, , burnout) cause damage to the adjacent electronic parts or the entire device.

A varistor (voltage nonlinear resistor, varistor) is used as an electronic component that protects electronic components and devices from such a problem. The varistor is used as a surge absorbing element since it has a voltage nonlinear resistance characteristic that abruptly decreases resistance in response to an increase in an applied voltage.

In the varistor, for example, a powder of zinc oxide is mixed with a trace amount of bismuth oxide powder, and the resultant is sintered at a temperature of 1000 [deg. C] or higher after molding into a disk using a metal mold, And electrodes are formed by connecting lead wires to the respective outer surfaces of the electrodes by soldering. The device is covered with an epoxy resin or the like to form a sheath. This enclosure functions to increase the mechanical strength and heat resistance of the varistor.

The varistor is generally used to protect electronic parts or devices from foreign or domestic surge, but when the varistor absorbs surges exceeding the absorption energy limit, it is damaged and short-circuited, and the exterior material may burn . The exterior material of the varistor is generally formed by an inorganic filler component and an epoxy resin component, and combustion of the exterior material is caused by combustion of the epoxy resin component.

For this reason, a flame-retardant material is used for the exterior material. As this flame retardant material, for example, an epoxy resin containing bromine or antimony which is a flame retardant is used. However, the epoxy resin is flame retardant, but there is a risk of burning if the varistor is heated and continues to generate heat. Once combusted, there is a possibility that the combustion continues until the flammable component in the exterior material disappears.

It is known to add a flame retardant of bromine or antimony to the flame-hardening of the casing. When the amount of the flame retardant is increased, the heating flow rate (fluidity) of the resin itself is lowered, making it difficult to form the exterior film. In the powder coating, when the amount of resin is 30 [wt%] or less, it becomes difficult to form an external coating. By reducing the combustible component of the exterior material to a combustion limit or less, the exterior material can be unfavorable.

The brominated flame retardant has a function of suppressing combustion of the resin component by gasification. The gasified bromine component tends to have a limited load on the environment, such as destruction of the ozone layer, and its use is limited.

With respect to external flame-hardening of such a varistor, a varistor using a silicone resin as a coating material excellent in flame retardancy is known as a protective coat instead of a brominated flame retardant (for example, Patent Document 1).

With respect to suppression of combustion of the silicone resin, the flame resistance of the exterior material is increased by adding aluminum hydroxide or magnesium hydroxide as a flame retardant to the silicone resin or the silicone elastomer, and the content of the ceramic itself or the exterior material itself A varistor suppressing scattering is known (for example, Patent Document 2).

Further, a varistor is known in which a curing agent is added to a liquid silicone base, and a silicone rubber containing aluminum hydroxide added to the base is coated as a sheath (see, for example, Patent Document 3).

Japanese Patent Application Laid-Open No. 6-215910 Japanese Patent Application Laid-Open No. 2005-277100 Japanese Patent Application Laid-Open No. 2006-286986

However, in an electronic component including a varistor, a higher overvoltage is required while maintaining the conventional overvoltage characteristics. In such electronic parts, the silicon-based resin material is indispensable, but is expensive.

Accordingly, an object of the present invention is to reduce silicon resin while maintaining the nonflammable and dielectric strength characteristics.

According to an aspect of the present invention, there is provided a method of manufacturing an electronic component using a casing material comprising a silicone resin, the method comprising the steps of controlling an addition amount in a range of 60% by weight to less than 70% by weight Wherein the non-polar solvent is evaporated by drying the exterior material formed on the surface of the element, and the silicone resin And a curing step of curing the exterior material.

In the above-described method of manufacturing an electronic component, the amount of the aluminum hydroxide or magnesium hydroxide added may be in the range of 60 wt% or more and 65 wt% or less.

In the above-described method for producing an electronic component, the average particle diameter of the aluminum hydroxide or the magnesium hydroxide may be in a range of 15 [mu m] to less than 50 [mu m].

In the above-described method for producing an electronic part, the non-polar solvent may have a vapor pressure of 0.5 to 10 [mu] m.

In order to achieve the above object, according to one aspect of the present disclosure, there is provided an electronic component using a casing member comprising a silicone resin, wherein a nonpolar solvent, aluminum hydroxide or magnesium hydroxide is added to the silicone resin, The amount of the magnesium hydroxide to be added is in the range of 60 wt% or more and less than 70 wt%, and the nonpolar solvent is exposed on the surface of the exterior material by evaporation, and the silicone resin is exposed on the surface of the exterior material And is cured.

In the electronic component, the average particle diameter of the aluminum hydroxide or the magnesium hydroxide may be in a range of 15 [mu m] or more and less than 50 [mu m].

In the electronic component, the casing may include aluminum hydroxide or magnesium hydroxide having a concentration gradient of 84 to 100 [%] within 30 [%] in the depth direction from the surface of the casing.

According to the present invention, any of the following effects can be obtained.

(1) The silicone resin can be reduced while maintaining the nonflammability and dielectric strength characteristics of the casing.

(2) Even when the varistor is instantly destroyed by application of the overvoltage exceeding the rated voltage, scattering of the external resin can be suppressed.

(3) The use amount of the silicone resin can be reduced, and the manufacturing cost can be reduced.

And other objects, features and advantages of the present invention will become more apparent by reference to the accompanying drawings and embodiments.

1 is a cross-sectional view showing a varistor according to the first embodiment.
Fig. 2 is a diagram showing the processing steps and the covering resin of the varistor manufacturing method.
3 is a view showing a dipping process of the external resin layer.
4 is a cross-sectional view showing the state of the exterior resin layer and the glass layer.
Fig. 5 is a view showing the result of an incombustible test.
6 is a diagram showing an experimental result of the withstand voltage.
7 is a view showing the evaluation result of the surface state of the external resin layer.

Figure 1 shows a section of a varistor.

This varistor 2 is a voltage nonlinear resistor and is an example of an electronic component of the present disclosure.

In this varistor 2, the surface of the voltage nonlinear resistance element (hereinafter, simply referred to as " element ") 4 is covered with a facer material 6. [ The element 4 is an example of a varistor element.

A ceramic body 8 is used for the element 4. The ceramic body 8 is, for example, a sintered body containing zinc oxide as a main component and containing magnesium oxide, bismuth oxide, cobalt oxide, and the like. The sintered body is, for example, a cylinder having a diameter of about 10 [mm].

On the surface of the ceramic body 8, electrodes 10-1 and 10-2 are provided. The lead wire 12-1 is connected to the electrode 10-1 by solder and the lead wire 12-2 is connected to the electrode 10-2 by solder.

The exterior material 6 includes an exterior resin layer 6-1 and a glass layer 6-2 as an example. The exterior resin layer 6-1 is an example of the first coating layer and the glass layer 6-2 is an example of the second coating layer.

2 (A) shows the manufacturing method of the varistor 2 in the order of process.

The production method of the varistor 2 includes a device forming step S1, a dipping step S2, a drying step S3, a curing step S4 and a coating step S5.

In the device forming step S1, the device 4 is formed. As the ceramic body 8 of the element 4, magnesium oxide, bismuth oxide, cobalt oxide, or the like is added to zinc oxide as a main component and sintered. The sintered body obtained by this sintering is, for example, a column having a diameter of about 10 [mm]. An electrode 10-1 is printed on one surface of the ceramic body 8 and an electrode 10-2 is printed on the other surface of the ceramic body 8 and fired.

Described lead wire 12-1 is connected to the electrode 10-1 by soldering and the lead wire 12-2 is connected to the electrode 10-2 by soldering.

After the step S1 of forming the element 4, the step goes to the dipping step S2. In this dipping step S2, the exterior resin layer 6-1 of the facings 6 is formed on the element 4 obtained in the element forming step S1. As the external resin layer 6-1, the external resin 14 is used as an example. As shown in Fig. 2B, aluminum hydroxide 18 and a solvent 20 are added to the silicone resin 16 for the external resin 14. [

The aluminum hydroxide 18 is added to the silicone resin 16 in the range of less than 70 (wt% = wt%). The range of the addition amount is more preferably 60 [wt%] or more and 65 [wt%] or less.

As the solvent 20, for example, a solvent type of a non-polar solvent may be used which has good homogeneity with the silicone resin 16. [ In the case of poor adhesion to the silicone resin 16, since the silicon resin 16 is repelled, bubbles remain in the exterior resin layer 6-1 due to the occurrence of pinholes during drying, Is important. As the non-polar solvent, for example, any of benzene, toluene, xylene, cyclohexane and the like may be used.

The addition of the solvent 20 makes it possible to lower the viscosity of the external resin 14 and increase the amount of the aluminum hydroxide 18 to be added to the external resin 14 to increase the formability of the external resin 14 . Furthermore, since the aluminum hydroxide 18 can be uniformly dispersed, deterioration of the withstand voltage due to unevenness of the aluminum hydroxide 18 in the planar direction of the external resin layer 6-1 can be prevented.

In this varistor 2, since the external resin layer 6-1 has a one-layer structure, unlike the two-layer structure, even if a pinhole occurs in the external resin layer 6-1, it can not be covered with the second layer . In other words, the external resin layer 6-1 of the varistor 2 needs to prevent the maldistribution of the aluminum hydroxide 18 and the pinholes while increasing the compounding ratio of the aluminum hydroxide 18 in order to improve the flame retardancy. Therefore, a solvent 20 of a non-polar solvent good in affinity with the aluminum hydroxide 18 is introduced into the silicone resin 16. [ In such a configuration, it is necessary to realize both of the improvement of the withstand voltage and the maintenance of the formability of the outer surface by preventing the maldistribution of the aluminum hydroxide 18 by lowering the viscosity without generating pinholes in the outer resin 14 . The non-polar solvent preferably has a vapor pressure (= volatile) of about 0.5 to 10 [deg.]. When the vapor pressure is high, pinholes are generated and the surface state of the external resin layer 6-1 is not preferable. On the other hand, when the vapor pressure is low, the surface condition of the external resin layer 6-1 is good, but it takes time to evaporate the solvent 20 in the drying step.

Fig. 3 shows the dipping treatment of the ceramic body 8 on the exterior resin 14. Fig.

As shown in Fig. 3 (A), the dip treatment tank 22 is filled with an outer resin 14 having a low viscosity. The surface of the element 4 is covered with the external resin 14 and the surface of the element 4 is covered with the external resin 14 as shown in Fig. An external resin layer 6-1 is formed.

After the dipping process, the process proceeds to the drying process S3. In this drying step S3, most of the solvent 20 is volatilized from the external resin 14 forming the external resin layer 6-1 of the element 4. In this step, the external resin 14 is not completely cured.

The drying step S3 is preferably carried out at room temperature (20 to 30 [deg.] C).

After the drying step S3, the process proceeds to the curing step S4. In this curing step S4, the exterior resin layer 6-1 is cured by heat treatment. The external resin layer 6-1 is formed by this curing. In the curing step S4, the solvent 20 remaining after the drying step S3 is evaporated by the heat treatment and the silicone resin component is exposed on the surface of the external resin layer 6-1. That is, by performing the heat treatment, the solvent 20 remaining in the external resin 14 moves to the surface of the external resin layer 6-1 and is exposed on the surface and evaporated. At this time, the silicone resin component is exposed on the surface of the exterior resin layer 6-1 together with the solvent 20 moving to the surface of the exterior resin layer 6-1. Thereafter, the exposed silicone resin component on the surface of the external resin layer 6-1 is cured by further heat treatment to give a gloss. The conditions of the curing process may be appropriately set, and the temperature may be set at 150 [deg.] C, for example, and the curing time may be set at 1 hour, for example.

This processing includes the first image shown in Fig. 4A and the second image shown in Fig. 4B. In the first region, a first region 611 and a second region 612 are formed on the surface of the element 4, as shown in Fig. 4A. The region 611 is a peeling layer and has a thickness of about 30%, for example, with respect to the whole resin thickness. The thickness of this region 611 is an example of the depth from the surface of the facings material 6. In the region 611, the aluminum hydroxide 18 from the surface of the peeling layer to the depth of 30 [%] has a concentration of about 84 to 100% of the resin blending ratio, for example. In the region 612, the aluminum hydroxide 18 at a concentration of 30% or more in the depth direction from the surface of the peeling layer has a concentration of, for example, about 100 to 109% of the resin blending ratio.

In the second region, a first region 621, a second region 622, and a third region 623 are formed. The area 621 is a peeling layer. From the surface of the peeling layer to the depth direction 30 [%], the aluminum hydroxide 18 has a concentration of, for example, about 84 to 100% of the resin blending ratio. The area 622 is a concentration of about 90 to 100% of the resin compounding ratio from the surface of the peeling layer to the depth direction 50 [%]. In the region 623, the aluminum hydroxide 18 has a concentration of about 100 to 119 [%], for example, in a resin composition ratio at a depth of 50% or more from the surface of the peeling layer. This concentration represents a concentration gradient due to the migration of the resin component at the time of curing, and this value is the maximum estimated value for the resin compounding ratio. Since the aluminum hydroxide 18 is supplied from the upper layer to the lower layer, the concentration of the upper layer obtained by subtracting the amount of the aluminum hydroxide 18 from the lower layer is the concentration range. This concentration range is an average value of the region, and it is considered that there exists a concentration portion locally lower than the lower limit value. Therefore, in this process, the range of the region may be reduced by 16% from the minimum value of the average of the regions 611 and 621, and the region 612 and 622 may be increased by 9% by the maximum value of the average.

The concentration of the aluminum hydroxide 18 is a value measured by Energy Dispersive X-ray spectrometry (EDX).

After the curing step S4, the coating step S5 is carried out. In this coating step S5, the surface of the external resin layer 6-1 is coated with glass. In this glass coating, the element 4 covered with the external resin layer 6-1 is immersed in, for example, silica sol to perform glass coating. The glass coat is cured by heat treatment to form a glass layer 6-2. Thereby, the varistor 2 shown in Fig. 1 is obtained.

≪ Effect of the embodiment &

The amount of the aluminum hydroxide 18 is less than 70% by weight, more preferably 60 to 65% by weight, based on the silicone resin 16, Can be reduced. Thus, the cost of the material cost and the like can be reduced.

(2) Addition of the solvent 20 to the external resin 14 makes it possible to suppress the increase in viscosity caused by the aluminum hydroxide 18. That is, by the lowering of the viscosity of the external resin 14 by the addition of the solvent 20, a large amount of the aluminum hydroxide 18 can be blended and the molding of the external resin layer 6-1 by the external resin 14 You can increase your sex.

(3) By the lowering of the viscosity of the external resin 14 by the addition of the solvent 20, the alumina hydroxide 18 can be prevented from being unevenly distributed in the external resin 14. This makes it possible to prevent a decrease in the withstand voltage of the varistor 2 due to the localization of the aluminum hydroxide 18 in the external resin layer 6-1. That is, excellent overvoltage characteristics are obtained.

(4) Since the silicone resin 16 can be exposed on the surface of the external resin layer 6-1 along with the evaporation of the solvent 20 in the curing process, the surface of the varistor 2 can be polished .

(5) Since the silicone resin 16 has flexibility, scattering of the external resin layer 6-1 can be suppressed even when the varistor is instantly broken by the application of the overvoltage exceeding the rated voltage.

(6) When the surface of the external resin layer 6-1 is in a shiny state and the crating of the varistor is printed on the surface of the external resin layer 6-1 with a laser The visibility of the image is improved.

(7) Further, by exposing the surface of the external resin layer 6-1 with the silicone resin 16, scratches on the surface are prevented from being formed, and scratch resistance is improved.

(8) Since the non-polar solvent is used for the solvent 20, pinholes can be prevented from being generated in the external resin layer 6-1 due to good homogeneity with the silicone resin 16. [ This also makes it possible to prevent a decrease in the withstand voltage of the varistor 2.

(9) The closer to the element 4 of the external resin layer 6-1, the higher the concentration of the aluminum hydroxide 18, so that the effect of suppressing the combustion of the element 4 is further improved.

<Experimental Results>

(1) Evaluation of incombustibility

This evaluation of the nonflammability relates to the flammability characteristic of the varistor (2). In this evaluation test, when an AC voltage of 85 [%] (varistor voltage V1 [mA] x 0.85) is applied, the external resin layer 6-1 of the exterior material 6, The time of discharge for each compounding ratio [wt%] was measured using the particle diameter [占 퐉] of the aluminum hydroxide 18 as a parameter. FIG. 5A shows the measured value, and FIG. 5B shows the graph. In Fig. 5B, "a" is an average particle diameter of 10 [mu] m, b is an average particle diameter of 15 mu m, c is an average particle diameter of 30 mu m, and d is an average particle diameter of 50 mu m.

In the evaluation of the incombustibility, as a criterion for judging the incombustibility due to the overvoltage breakage, the incombustibility was judged to be less than 1 [sec].

According to this evaluation test, if the average particle diameter is 30 [mu m] or more, the flame-out time is less than 1 [sec] if the compounding ratio is 55 [wt% or more,

Even if the average particle size is less than 30 [mu] m, if the compounding ratio is 60 (wt%) or more, the flame-out time is less than 1 second and the flame-retardancy is recognized.

Even if the average particle diameter is from 10 [mu] m to 50 [mu m], if the blending ratio is 65 [wt%] or more, the flame-out time becomes 0.5 seconds or less and good nonflammability is recognized.

When the aluminum hydroxide 18 is added to the silicone resin 16 in the range of less than 70 wt%, the incombustibility is less than 1.0 seconds, and the addition amount of the aluminum hydroxide 18 When the range is 60 [wt%] or more and 65 [wt%] or less, the nonflammability is more preferably obtained. Therefore, the incombustibility of the varistor 2 can be increased while reducing the silicon resin 16.

(2) Evaluation of dielectric strength

In the evaluation test of the dielectric strength, dielectric breakdown of the blend ratio [wt%] was measured using the particle diameter [占 퐉] of the aluminum hydroxide 18 as a parameter. FIG. 6A shows the measured value, and FIG. 6B shows the graph. In Fig. 6B, b is an average particle diameter of 15 mu m, c is an average particle diameter of 30 mu m, and d is an average particle diameter of 50 mu m.

In the evaluation of the insulation withstand voltage, it is judged that an insulation withstand voltage effect is not less than 10 [kV / mm] with respect to the breakdown voltage [kV / mm].

According to this evaluation test, when the compounding ratio is 65 [wt%] or less irrespective of the average particle diameter of 15 [탆], 30 [탆] and 50 [탆], an insulation withstand voltage of 10 [kV / mm] .

Therefore, when aluminum hydroxide 18 is added to the silicone resin 16 in the range of less than 70 wt%, preferably 60 wt% to 65 wt% The overvoltage characteristic of the varistor 2 can be maintained. It is most preferable that the average particle diameter is 30 [mu m] for a compounding ratio of 60 [wt%] to 65 [wt%].

(3) Evaluation of surface condition

In the evaluation test of the surface state, the surface property of the external resin layer 6-1 formed on the element 4 is visually observed. Fig. 7 shows the result of the evaluation.

In this evaluation, when the gloss of the surface of the exterior resin layer 6-1 was judged to be glossy, the glossiness was evaluated as?, The glossiness was retreated as?, And the glossiness was lost as?.

In this gloss evaluation, when the compounding ratio of the aluminum hydroxide 18 is 70 [wt%] regardless of the particle diameter, the gloss of the surface is lost.

Although the gloss of the surface of the external resin layer 6-1 does not directly affect the function of the varistor 2, it is preferable that the surface of the external resin layer 6-1 has gloss Do. There is also a case where the surface of the external resin layer 6-1 is laser-printed with a varistor rating or the like. At this time, when the surface of the glossy resin layer 6-1 is laser-printed, the surface state is improved compared with the uneven state. The formation of the glossy layer alleviates the roughness of the surface state due to the high mixing of the aluminum hydroxide 18, and is effective in preventing appearance damage and scratches due to friction between the products in a packed state.

[Other Embodiments]

(1) In the above embodiment, the coating step S5 is performed after the curing step S4 to form the glass layer 6-2 by performing the glass coating on the surface of the external resin layer 6-1. However, the glass layer 6- 2) may not be formed.

(2) In the above embodiment, the case where the exterior resin 14 forming the exterior resin layer 6-1 is added with the aluminum hydroxide 18 and the solvent 20 to the silicone resin 16 is shown. However, But is not limited thereto. Magnesium hydroxide may be added to the silicone resin 16 together with the solvent 20 as a flame retarding agent.

Magnesium hydroxide is added to the silicone resin 16, for example, in a range of less than 70 wt% (wt%). The range of the added amount is more preferably set to 60 [wt%] or more and 65 [wt%] or less. The magnesium hydroxide has a density of 2.36 g / cm &lt; 3 &gt;, and the density of aluminum hydroxide is approximately equal to 2.42 g / cm &lt; 3 &gt;. Therefore, the amount of magnesium hydroxide to be added may be set equal to that in the case of adding the above-described aluminum hydroxide 18, for example, based on the weight ratio to the silicone resin (16).

The average particle diameter of magnesium hydroxide may be set in a range of, for example, 15 [mu m] or more and less than 50 [mu m]. In addition, in the process of forming the external resin layer 6-1 of the varistor 2 when magnesium hydroxide is added to the external resin 14, as in the case of adding the aluminum hydroxide 18 shown in the above embodiment And the forming conditions of the external resin layer 6-1 are set, and the processing procedure may be performed in the same manner.

(a) According to this constitution, the outer resin 14 to which magnesium hydroxide is added can set the dewatering start temperature higher than when the aluminum hydroxide 18 is added. That is, the external resin 14 has a dehydration initiation temperature of about 200 [deg.] C when aluminum hydroxide is added and a dehydration initiation temperature of about 300 [deg.] C when magnesium hydroxide is added. When the varistor 2 generates local heat accompanied by surge, the exterior material 6 becomes "dehydrated" → "vaporized" → "expanded" → "resin peeling" → "spark" → "failure mode" The varistor 2 can function even when the dehydration start temperature of the external resin 14 is lowered at a high temperature due to the increase in the temperature of the external resin 14. This makes it possible to use the varistor 2 in electronic equipment which is likely to be supplied with a larger surge voltage.

the silicone resin 16 can be reduced by adding the magnesium hydroxide (b) less than 70 wt%, more preferably 60 to 65 wt%, based on the silicone resin (16). Thus, the cost of the material cost and the like can be reduced.

(c) Addition of the solvent (20) to the external resin (14) makes it possible to suppress the increase in viscosity caused by the magnesium hydroxide. That is, by the lowering of the viscosity of the external resin 14 by the addition of the solvent 20, a large amount of magnesium hydroxide can be blended and the moldability of the external resin layer 6-1 by the external resin 14 is increased .

(d) By lowering the viscosity of the external resin 14 by the addition of the solvent 20, it is possible to prevent the localization of magnesium hydroxide in the external resin 14. This makes it possible to prevent the dielectric breakdown voltage of the varistor 2 from being lowered by the magnesium hydroxide localization in the external resin layer 6-1. That is, excellent overvoltage characteristics are obtained.

(e) Since the silicone resin 16 can be exposed on the surface of the external resin layer 6-1 along with the evaporation of the solvent 20 in the curing step, the surface of the varistor 2 can be polished .

(f) Since the silicone resin 16 has flexibility, scattering of the external resin layer 6-1 can be suppressed even when the varistor is instantly broken by the application of the overvoltage exceeding the rated voltage.

(g) The surface of the external resin layer 6-1 is in a glossy state, and the visibility when the varistor rating or the like is printed on the surface of the external resin layer 6-1 with a laser is improved.

(h) Furthermore, by exposing the surface of the external resin layer 6-1 with the silicone resin 16, scratches on the surface are prevented from being formed, and scratch resistance is improved.

(i) Since the non-polar solvent is used for the solvent 20, pinholes can be prevented from being generated in the external resin layer 6-1 due to good homogeneity with the silicone resin 16. [ This also makes it possible to prevent a decrease in the withstand voltage of the varistor 2.

(j) Since the concentration of magnesium hydroxide is closer to the element 4 of the external resin layer 6-1, the effect of suppressing the combustion of the element 4 is further improved.

As described above, the most preferred embodiment of the present invention has been described. The present invention is not limited to the above description, and various modifications and changes may be made by those skilled in the art based on the gist of the invention disclosed in the specification or the detailed description for carrying out the invention. It goes without saying that such variations and modifications are included in the scope of the present invention.

The technique of the present disclosure can reduce the use amount of aluminum hydroxide or magnesium hydroxide by adding aluminum hydroxide or magnesium hydroxide to the silicone resin contained in the outer cover material of the varistor while maintaining the fire retardancy possessed by the silicone resin, And so on.

2: varistor
4: Voltage nonlinear resistance element
6: Outer material
6-1: External resin layer
6-2: Glass layer
8: Ceramic body
10-1, 10-2: electrode
12-1, 12-2: Lead wire
14: external resin
16: silicone resin
18: Aluminum hydroxide
20: Solvent
22: Dip treatment tank
611, 621: first region
612, 622:
623: third region

Claims (7)

A method of manufacturing an electronic component using an exterior material comprising a silicone resin,
A step of dipping the element into a casing containing aluminum hydroxide or magnesium hydroxide controlled in an amount of not less than 60% by weight and less than 70% by weight, and a silicone resin to which a non-polar solvent is added;
Drying the exterior material formed on the surface of the device to evaporate the non-polar solvent and exposing a silicone resin component to the surface of the exterior material;
A curing process for curing the exterior material
Wherein the step of forming the electronic component comprises the steps of: The method of manufacturing an electronic component according to claim 1, wherein the amount of the aluminum hydroxide or magnesium hydroxide is in the range of 60 wt% or more and 65 wt% or less. The method for manufacturing an electronic part according to claim 1 or 2, wherein the average particle diameter of the aluminum hydroxide or the magnesium hydroxide is in a range of 15 [mu m] or more and less than 50 [mu m]. The method of manufacturing an electronic part according to any one of claims 1 to 3, wherein the non-polar solvent has a vapor pressure of 0.5 to 10 [micro]. An electronic component using an exterior material comprising a silicone resin,
Wherein a nonpolar solvent, aluminum hydroxide or magnesium hydroxide is added to the silicone resin, the amount of the aluminum hydroxide or magnesium hydroxide to be added is in the range of 60 wt% or more and less than 70 wt%, and the non- Wherein the silicone resin is exposed on the surface of the casing and evaporated, and the silicone resin is exposed and cured on the surface of the casing. The electronic component according to claim 5, wherein the average particle diameter of the aluminum hydroxide or the magnesium hydroxide is in the range of 15 [mu m] to less than 50 [mu m]. 7. The method according to claim 5 or 6, characterized in that the exterior material comprises aluminum hydroxide or magnesium hydroxide having a concentration gradient of 84 to 100 [%] within 30 [%] in the depth direction from the surface of the exterior material Electronic parts.

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